There has been a long felt need for technologies that would prevent terrorism, catch terrorists in the act, and let law-abiding citizens go about their business without the loss of convenience or privacy. The attacks of September 11 have accelerated the search for effective technologies to prevent further attacks using weapons of mass destruction, such as radioactive bombs, and biological agents, such as anthrax. Many public and private organizations and institutions are researching and testing various tools and techniques to meet security and anti-terrorism objectives.
Some of these tools and techniques use artificial intelligence to model and replicate human ability to analyze information, with the hope to automate aspects of detection. Biometrics uses body parts and features to identify and authenticate people. Electromagnetic wave-based technologies use devices such as metal detectors, wave cameras, radio frequency identification tags, and X-rays to detect materials and identify and verify various items. Still other technologies and techniques include forensic analysis, such as DNA sampling and forensic psychology.
As is known in the art, detection systems include video-based solutions that use image processing techniques to detect changes in pixels corresponding to the presence of objects within a video camera's field of view. Other known detection systems include infrared break-beam solutions that require objects to occlude multiple infra-red signals to detect objects within an area of interest.
Radar is a suitable technology for implementing a sensor for use in detection of objects, such as automobiles, trucks, and cargo vessels. One type of radar suitable for this purpose is Frequency-Modulated Continuous-Wave (FMCW) radar. In typical FMCW radar, the frequency of the transmitted CW signal linearly increases from a first predetermined frequency to a second predetermined frequency. FMCW radar has the advantages of high sensitivity, relatively low transmitter power, and good range resolution.
One example FMCW radar solution is the Multi-beam Radar (MBR) from Valeo-Raytheon Systems which in one example configuration is a 24 gigahertz FMCW radar including 7 receive beams and 1 transmit beam. Many of these units are in manufacture and their low cost and good performance make them useful in various applications, such as is in near-object detection systems which may be of the type described in U.S. Pat. No. 6,784,828, entitled “Near Object Detection System,” issued Aug. 31, 2004, presently assigned to Raytheon Company of Lexington, Mass.